patches/kernel/0052-objtool-Don-t-report-end-of-section-error-after-an-e.patch

   1 From 985d8e62ef5f1b006da5e175858e552c0dbda771 Mon Sep 17 00:00:00 2001
   2 From: Josh Poimboeuf <jpoimboe@redhat.com>
   3 Date: Mon, 18 Sep 2017 21:43:30 -0500
   4 Subject: [PATCH 052/241] objtool: Don't report end of section error after an
   5  empty unwind hint
   6 MIME-Version: 1.0
   7 Content-Type: text/plain; charset=UTF-8
   8 Content-Transfer-Encoding: 8bit
   9
  10 CVE-2017-5754
  11
  12 If asm code specifies an UNWIND_HINT_EMPTY hint, don't warn if the
  13 section ends unexpectedly.  This can happen with the xen-head.S code
  14 because the hypercall_page is "text" but it's all zeros.
  15
  16 Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
  17 Cc: Andy Lutomirski <luto@kernel.org>
  18 Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
  19 Cc: Jiri Slaby <jslaby@suse.cz>
  20 Cc: Juergen Gross <jgross@suse.com>
  21 Cc: Linus Torvalds <torvalds@linux-foundation.org>
  22 Cc: Peter Zijlstra <peterz@infradead.org>
  23 Cc: Thomas Gleixner <tglx@linutronix.de>
  24 Link: http://lkml.kernel.org/r/ddafe199dd8797e40e3c2777373347eba1d65572.1505764066.git.jpoimboe@redhat.com
  25 Signed-off-by: Ingo Molnar <mingo@kernel.org>
  26 (cherry picked from commit 00d96180dc38ef872ac471c2d3e14b067cbd895d)
  27 Signed-off-by: Andy Whitcroft <apw@canonical.com>
  28 Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
  29 (cherry picked from commit 9d22f903bba24f2ac86de8a81dc1788f9957aca8)
  30 Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>
  31 ---
  32  tools/objtool/check.c | 7 +++++--
  33  1 file changed, 5 insertions(+), 2 deletions(-)
  34
  35 diff --git a/tools/objtool/check.c b/tools/objtool/check.c
  36 index 368275de5f23..0a86fd0ac082 100644
  37 --- a/tools/objtool/check.c
  38 +++ b/tools/objtool/check.c
  39 @@ -1652,11 +1652,14 @@ static int validate_branch(struct objtool_file *file, struct instruction *first,
  40                 if (insn->dead_end)
  41                         return 0;
  42
  43 -               insn = next_insn;
  44 -               if (!insn) {
  45 +               if (!next_insn) {
  46 +                       if (state.cfa.base == CFI_UNDEFINED)
  47 +                               return 0;
  48                         WARN("%s: unexpected end of section", sec->name);
  49                         return 1;
  50                 }
  51 +
  52 +               insn = next_insn;
  53         }
  54
  55         return 0;
  56 --
  57 2.14.2
  58